import 'dart:io';

import 'package:dio/dio.dart';
import 'package:worldhopper/models/entry.dart';
import 'package:worldhopper/models/server.dart';
import 'package:worldhopper/models/stream_link.dart';
import 'package:worldhopper/services/auth_service.dart';
import 'package:worldhopper/services/epub_download_service.dart';
import 'package:worldhopper/services/image_stream_download_service.dart';
import 'package:worldhopper/services/opds_parser.dart' show ParsedFeed;
import 'package:worldhopper/services/opds_service.dart';
import 'package:worldhopper/services/server_software/server_software.dart';

/// OPDS implementation of [ServerSoftware].
///
/// Wraps the existing OPDS service layer (fetching XML feeds, PSE page
/// streaming, HTTP Basic Auth) to implement the full server interface.
/// This is the default/fallback implementation for generic OPDS servers.
class OPDSServerSoftware implements ServerSoftware {
  final OPDSService _opdsService;
  final AuthService _authService;
  final EpubDownloadService _epubDownloadService;
  final ImageStreamDownloadService _imageStreamDownloadService;

  OPDSServerSoftware({
    OPDSService? opdsService,
    AuthService? authService,
    EpubDownloadService? epubDownloadService,
    ImageStreamDownloadService? imageStreamDownloadService,
  })  : _opdsService = opdsService ?? OPDSService(),
        _authService = authService ?? AuthService(),
        _epubDownloadService = epubDownloadService ?? EpubDownloadService(),
        _imageStreamDownloadService =
            imageStreamDownloadService ?? ImageStreamDownloadService();

  @override
  bool detectFromUrl(Server server) => true; // OPDS is the fallback

  @override
  Future<bool> testConnection(Server server, {CancelToken? cancelToken}) async {
    return _opdsService.testConnection(server, cancelToken: cancelToken);
  }

  @override
  Future<ParsedFeed> fetchRootFeed(Server server,
      {CancelToken? cancelToken}) async {
    return _opdsService.fetchRootFeed(server, cancelToken: cancelToken);
  }

  @override
  Future<ParsedFeed> fetchFeed(Server server, String url,
      {CancelToken? cancelToken}) async {
    return _opdsService.fetchFeed(server, url, cancelToken: cancelToken);
  }

  @override
  Future<Map<String, EntryProgress>> fetchEntryProgress(
    Server server,
    List<Entry> entries,
  ) async {
    // For OPDS, progress is already embedded in StreamLink.lastRead from the
    // feed response. Extract it from the entries directly.
    final result = <String, EntryProgress>{};
    for (final entry in entries) {
      if (entry.hasStreamLink &&
          entry.streamLink!.lastRead != null &&
          entry.streamLink!.lastRead! > 0) {
        result[entry.id] = EntryProgress(
          entryId: entry.id,
          currentPage: entry.streamLink!.lastRead!,
          totalPages: entry.streamLink!.pageCount,
        );
      }
    }
    return result;
  }

  @override
  Future<void> reportPageProgress(
      Server server, StreamLink streamLink, int page) async {
    await _opdsService.reportPageProgress(server, streamLink, page);
  }

  @override
  Future<void> reportEpubProgress(
    Server server,
    Entry entry,
    double progress,
  ) async {
    // Generic OPDS has no standard EPUB progress endpoint.
  }

  @override
  Future<void> markAsRead(Server server, Entry entry) async {
    // PSE-based: fetch the last page URL to trigger server-side progress
    if (entry.hasStreamLink) {
      await _opdsService.markAsRead(server, entry.streamLink!);
    }
  }

  @override
  Future<void> markAsUnread(Server server, Entry entry) async {
    // No-op for generic OPDS — PSE has no unread concept
  }

  @override
  Future<File> downloadEpub(
    Server server,
    Entry entry, {
    String? savePath,
    void Function(double progress)? onProgress,
    CancelToken? cancelToken,
  }) async {
    return _epubDownloadService.downloadEpub(
      entry,
      server,
      savePath: savePath,
      onProgress: onProgress,
      cancelToken: cancelToken,
    );
  }

  @override
  Future<String> downloadImageStreamChapter({
    required Server server,
    required StreamLink streamLink,
    required String seriesId,
    required String chapterId,
    void Function(int downloaded, int total)? onProgress,
    CancelToken? cancelToken,
  }) async {
    return _imageStreamDownloadService.downloadChapter(
      server: server,
      streamLink: streamLink,
      seriesId: seriesId,
      chapterId: chapterId,
      onProgress: onProgress,
      cancelToken: cancelToken,
    );
  }

  @override
  Map<String, String> getAuthHeaders(Server server) {
    return _authService.getAuthHeaders(server);
  }

  @override
  void clearCachedState(String serverId) {
    _opdsService.clearClient(serverId);
  }
}